Electric Kit for Whyte Suffolk 2017

[jaron08]

Hello All,

I hope that I can get some advice as I was trawling through the internet and did not find any specific information on the subject.

I would like to electrify my Whyte Suffolk 2017. What's the problem?
Well, its drop handlebars and brake levers which cover the gear shifters.

I was thinking about the mid-drive train, Banfang BS02 would suit me well.

However, how would I go about installing the brake levers for motor cut off?

Thank you very much for any advice, much appreciated.

 

[Woosh]

best kit for lightweight road bikes with drop bars and STI levers is the 48V TSDZ2. You get power, lightness, simple wiring and torque sensor. You don't need to fit brake cut out sensors.

http://wooshbikes.co.uk/?cdkit#tsdz2

 

[jaron08]

Hi,

Thank you very much for coming back to me. So, I assume there would be no throttle either? All would concentrate on pedal assist? If I wanted to go faster I just pedal faster and likewise with losing speed?

 

[Woosh]

no throttle, only pedal assist. The harder you push on the pedals, the more the motor gives.
there are 4 assist levels (eco, tour speed and turbo) + zero assist.
The motor weighs 2.64kgs and can give up to 100NM torque. This is a 48V motor, about 30% more power than the 36V unit.
Road legal.

This is how it looks on a road bike:

 

[jaron08]

That's precisely what I am after. However, I am a little bit concerned about the inability of cutting off the motor, especially if I was to go for more than 250W.
Would in-line brake cut-out sensors solve that problem well?
https://www.brightonebikes.co.uk/store/p66/In-line_brake_cut-out_sensors_(Higo_connector)_for_Bafang_BBS01/02/HD_-_Pair.html

My bike is more of a gravel bike with enough clearance to fit fatter tyres. Thus, I was considering Bafang to go occasionally for some off-road rides.

 

[Woosh]

bikes that run with a torque sensor do not need brake cutoffs because the motors do not overrun like bikes that work with a cadence sensor.
People instinctively reduce pedal pressure when turning a tight spot or braking, the motor instantly reduces its output accordingly.
Brake cutoffs are still necessary if you have a throttle because the throttle can potentially gets stuck in the active state.
The TSDZ2T with throttle comes with brake sensored levers for cable operated brakes.

 

[jaron08]

I see your point. However, I also see the potential to install the throttle on the drop handlebars. I reckon that a piece of PVC pipe and zip cables would do the job.

Then, given all that. Do you think its worth to install one of the Bafang's more powerful mid-drive motors with in-line brake cut off sensor and throttle?

I do understand that I'd have torque PAS and an additional boost from throttle when needed on some off-road rides?
I would like to settle for 750W with some fairly decent battery capacity, say 48V 18Ah?

 

[RobF]

It's tempting to want more power because more power is always better. right?

Wrong - in a lot of cases.

Unless you want what would be an underpowered moped, in which case you would be far better buying a petrol moped - loads more poke and range than any ebike kit.

Put another way, there are a couple of long term users of the 750w Bafang crank drive on the forum.

Both have turned the motor power down to make the rig more usable.

 

[jaron08]

That is a natural assumption of e-bike newbies like myself, yes!

As an expert, what would you consider an absolute top capacity to make it useable enough for bike purposes but still allow some off-road fun rides every once in a while?

Let me explain my situation to shed some more light on the requirements.

I live in a quite hilly area of Yorkshire. I use my bike for an everyday office commute on the road which is ridden with potholes. That was one of the reasons to start using fatter tyres, I had switched from 26cc to 30cc. Yes, it got much more comfortable but slower nonetheless. I'm 24 y.o and consider myself rather fit (not a bike racer though by any measure). Prior to buying my Whyte Suffolk, I would always go on some off-road MTB rides to woods. I wanted something that would allow me for a comfortable commute and occasional off-road fun on fatter tyres (hence my choice to buy a bike with enough clearance).

Given all that, would 500W be more than enough then?

I really appreciate your opinions btw. I'm glad that I've sought some help rather than making foolish decisions by myself .

 

[vfr400]

You don't need to get hung up on 250w or 500w. It's meaningless and doesn't give you any idea of how much power the motor will give. Power comes from the battery and is regulated by the controller. You feel torque as power. Torque is what makes the bike move. The more torque you have, the faster you can accelerate and the steeper you can climb. Power ultimately dictates how fast you can go as long as there aren't other restrictions, like gearing and motor speed. Very roughly, torque is proportional to the amount of current the controller allows. The power you get is roughly battery volts times controller current times 0.7 (0.7 x volts x amps). You can get 250w systems that range from 12 amps at 24v to 20 amps at 48v, i.e 201w to 672w and 500W systems are normally around 36v and 22 amps, so 554w.

Electric motors don't behave like petrol motors. They make high torque at low RPM. Efficiency is very important with an electric motor because if you run with low efficiency, the motor will overheat and waste battery. Electric motors make low efficiency at low speed and max efficiency at about 75% of their maximum speed.

If you use a crank motor, you're not so constrained by efficiency as long as you have the right cadence and are in the right gear. The downside is a lot of gear-changing and wear ion your drive train.

If you use a hub-motor, you get a much more relaxing ride because the motor works independently from the gearing. the downside is that you have to choose a motor with a speed that matches your modal riding speed, and you get low efficiency if you go too slow.

Your bike is a road bike with thin tyres. High power will be a liability because the torque from the motor will cause the tyre to lose traction, especially in the wet.

There are too many variables with the different motors and systems to give you any sensible specific advice unless you're honest and tell us exactly what you want to do with the bike. If you want to go off-road, surely an MTB would be better. All the different motors and systems each have their own advantages and disadvantages.

 

[jaron08]

Thank you very much for this extensive answer. It has opened my eyes quite a bit!

Ok, let me be straight with the intended use then:
- 60% of the time it will be used for commuting to and from work. I would like to climb the hills without breaking too much sweat really. The area where I live is quite hilly with a steep gradient. Moreover, there is quite a lot of open spaces. So, often times we get a fairly strong wind. I found myself at times pedalling and not moving forward, that's how bad it gets. I'm not that particularly bothered about the speed but convenient transport mode which will get me from point A to point B in a relatively quick and efficient way. I've got to cover about 14 miles a day, both ways.
- 40% of the time it will be some leisure weekend rides with my girlfriend (whose bike I'm planning on electrifying too). We live close to Yorkshire Dales. So, there will be plenty of times when we'll be out and about. From my past experience, we could cover as much as 20-30 miles a day. However, if we had electric drive trains we could easily go for weekend trips covering twice as long distances.

The roads which are around us are about 70% asphalt, 15% tarmac, and 15% fire roads.
Based on the above, could you please kindly recommend the most accurate motor, system, battery with their respective parameters. Also, what set of tyres would be best to go along with the above.

Thank you very much to you all for your advice and time.

P.S
If you could also recommend the best sources to buy these components from I would be more than grateful.

 

[vfr400]

A Woosh XF08 CST rear cassette motor kit will give you what you want or a Yose Power cassette motor kit. I'm assuming that you have 700c wheels. Both have a choice of batteries to suit.

http://wooshbikes.co.uk/?hubkits

https://www.yosepower.com/en/product/Hub-Motor-36V350W-28"-Rear-Motor-with-Cassette-Bicycle-E-Bike-Hub-Conversion-Kit-Silver-DIY-E-bike-LCD-Display-123.html

 

[jaron08]

Yes, I do have 700c wheels. However, I also have hydraulic brakes which from what I see are not suitable for these conversion kits.

How about the initial suggestion from Whoosh and going along with TSDZ2?
They do not have a kit with battery included. So, my predicament would be the optimal pack that would go well with it.
I do assume that it would be suitable with any sort as long as its 48V.

 

[Nealh]

There are ways to adopt brake cut offs for hydraulic and you only need to fit one, how you go about it depends on the design/actuation of your hdb.
I carefully butcher the lever for the complete wired push sensor, attach it with epoxy (gorilla) to the brake body and fashion a small right angled ali piece to epoxy on the lever, pulling the brake lever releases the pressure on the sensor push actuating the cut out.